You have to release her
i mean you can build the monsterhall by talking to the builder in your castle/by talking to that guy you get a map overview where you can build the big farm and monsterhall and then you have the farm from the snow place, in each place you can only put the requested monster, example the farm at snow place, you can only put an imp or something else and at the monsterhall you can put slimes or others.
hope you know what i mean :)
